Digimarc Corporation

Other

Clayton L Davidson

Aruna B Kumar

Geoffrey B Rhoads

Tony F Rodriguez

Stephen K Decker

Lance Lixin Shen

John O Ryan

James R Holzgrafe

Patrice J Capitant

Kordian Jacek Kurowski

Tony Forrest Rodriquez

Andrew Mellows

This patent document details, e.g., claims and systems for watermark decoding from streaming media signals. One claim recites an apparatus comprising: electronic memory for buffering a streaming media signal; one or more electronic processors programmed for: ranking buffered portions of the media signal in terms of their ability to hide steganographic indicia; detecting steganographic indicia from relatively higher-ranked portions of the streaming media signal before attempting to detect from relatively lower-ranked portions; and carrying out an action based at least in part on detection of the steganographic indicia. Of course, other claims and disclosure are provided too.

Watermark decoding from streaming media

A method of embedding auxiliary data in coefficients generated for a compressed data stream applies embedding rules to selected coefficients in different blocks to embed the data. The method receives coefficients in a data stream in which the coefficients are divided into blocks. It changes the value of selected coefficients to embed multi-bit message data in the coefficients. The process of changing the coefficients includes controlling changes to the selected coefficients from different blocks so that the relationship of the selected coefficients from the different blocks satisfy an embedding rule. One embedding rule causes the embedded data to form a pattern across the blocks. Another rule causes coefficients of blocks to have a desired phase relationship. Another rule enforces entropy and/or bit rate constraints onto the data stream. These embedding rules facilitate data hiding within bit rate and perceptibility constraints, while increasing robustness.

Watermarking compressed data

The disclosure describes pattern recognition detectors and software used to detect patterns in image streams. The detectors operate on streams of image data, making them suitable for detecting certain types of patterns in documents and images passed between processes and devices. For instance, the streaming mode detectors operate in printer drivers on streams of image data being passed to a printer. Also, the streaming mode detectors operate in scanner drivers on streams of image data being passed from a scanner. The disclosure describes pattern detectors for shapes with complex features as well as objects comprised of many smaller shapes. The disclosure also describes novel raster line and edge tracing pattern techniques.

Pattern recognition of objects in image streams

The disclosure details methods and systems for watermark encoding and decoding. In one implementation a method is provided to detect steganographic indicia embedded in a streaming media signal. The method includes receiving a streaming media signal; caching selected portions of the streaming media signal; detecting steganographic indicia from cached portions of streaming content; and carrying out an action based at least in part on detection of the steganographic indicia. Additional solutions, methods and implementations are detailed in the disclosure.

Watermark encoding and decoding

The disclosure describes pattern recognition detectors and software used to detect objects in image streams. The detectors operate on streams of image data, making them suitable for detecting certain types of objects in documents and images passed between processes and devices. For instance, the streaming mode detectors operate in printer drivers on streams of image data being passed to a printer. Also, the streaming mode detectors operate in scanner drivers on streams of image data being passed from a scanner. The disclosure describes pattern detectors for shapes with complex features as well as objects comprised of many smaller shapes. The disclosure also describes novel raster line and edge tracing pattern techniques.

The invention provides methods and related systems for embedding and detecting watermarks in images, such as JPEG or MPEG formatted images as well as other types of image signals. One method receives transform coefficients of the image, and changes the value of selected coefficients to embed watermark data in the coefficients. The changing of the coefficients is controlled such that it both embeds the data and forms an orientation signal that facilitates determination of rotation or scale of the image. Another aspect of the invention is a variation of embedding a watermark in an image. This method receives message bits to be embedded in the image, receives transform coefficients of the image, and maps the message bits to selected transform coefficients. The method changes the value of selected coefficients to embed data in the coefficients. The characteristics of the image are used to control the change of transform coefficients to embed the watermark, and a bit rate control is used to modify the change of transform coefficients to embed the watermark according to a bit rate limit.

Transform domain watermarking of image signals

The disclosure details methods and systems for watermark encoding and decoding in imaging devices, such as printers and scanners, and imaging device interfaces. Watermark encoding and decoding functions are incorporated into printer and scanner image processing pipelines. Watermark encoders and decoders perform watermark encoding and decoding, respectively, on an image as it is being transferred from one stage of a printing or scanning process to another. In particular, streaming mode watermark encoders and decoders operate on sequential portions of the image in a sequential image stream passing from one stage to another. The streaming mode encoder and decoder may be incorporated in a printer or scanner driver in a computer connected to a printer or scanner peripheral or within a printer or scanner device.

Watermark encoding and decoding in imaging devices and imaging device interfaces

Method and apparatus for &ldquo;copy-once&rdquo; of a digital video signal uses a watermark in the video signal. The embedded watermark has two versions: one indicates copy-never and a second indicates copy-once, the difference being a single watermark bit. The watermark carries additional bits representing a digitized attribute (image characteristic) of a particular video frame of the video signal, for instance an average value of the amplitude of a video field. The frame whose attribute is carried in the watermark has a field (or frame) marker, which is a special signal located in the overscan portion of the frame. A compliant video recorder verifies the watermark and the copy-once bit, extracts the associated attribute from the watermark, and compares it to the measured attribute of the marked video frame. Only if the extracted attribute value and the measured attribute value match is recording enabled. During the recording process, the frame markers are stripped, preventing second generation copies of the recorded video signal, and the copy-once bit is set to copy-never.

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Lake Oswego, OR, United States of America

Clayton L Davidson